As mentioned, the study ultimately found that cell death and DNA mutations occurred. However it’s important to note that, while telling, this study was done in vitro (in petri dishes) and not on actual humans (in vivo). “This is the only way to study a change without actually having to do biopsies and exposing humans to live radiation, exposure, etc.,” says San Diego-based Plastic Surgeon, Dr. Amir Karam. In this case, they used cells derived from humans and mice (as a control to see if it has the same effect in the animal cell line). Researchers observed that after 20 minutes, 20% to 30% of the cells had died. After three consecutive 20-minute sessions, 65% to 70% of cells had died. Translation: The more frequent the use of the lamp, the higher the cell-death rate. “What this [new] study has shown is that there are changes that kill the cell, which is probably not the biggest deal (if a skin cell dies, it dies; but the more concerning issue is the [cancer-causing] mutation that it creates,” explains Dr. Karam.